AIR CONDITIONING SYSTEM(for Automatic Air Conditioning System), Diagnostic DTC:B1442/42

DTC Code DTC Name
B1442/42 Air Inlet Damper Control Servo Motor Circuit

DESCRIPTION

The blower damper servo sub-assembly (air inlet) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the air inlet mode selection blower damper servo sub-assembly (air inlet) to the appropriate position, which controls the air inlet mode (fresh, recirculation/fresh, and recirculation).

The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory
B1442/42 Air Inlet Damper Control Servo Motor Circuit Air inlet damper position sensor value does not change even if air conditioning amplifier assembly operates blower damper servo sub-assembly (air inlet)

  • Blower damper servo sub-assembly (air inlet)

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

Memorized

(30 sec. or more)*1

WIRING DIAGRAM

A002C4GE45

CAUTION / NOTICE / HINT

Tech Tips

Confirm that no mechanical problems are present because this DTC can be output when either a damper link or damper is mechanically locked.

PROCEDURE


  1. READ VALUE USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Operate the recirculation/fresh switch.

    5. Enter the following menus: Body Electrical / Air Conditioner / Data List.

    6. Check the value(s) by referring to the table below.


      Body Electrical > Air Conditioner > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Air Inlet Damper Targ Pulse Blower damper servo sub-assembly (air inlet) target pulse

      Min.: 128

      Max.: 383

      • Recirculation: 7 (pulse)

      • Fresh: 28 (pulse)

      		 -
      Air Inlet Damper Actual Pulse Blower damper servo sub-assembly (air inlet) actual pulse

      Min.: 128

      Max.: 383

      • Recirculation: 7 (pulse)

      • Fresh: 28 (pulse)

      		 -

      Body Electrical > Air Conditioner > Data List
      Tester Display
      Air Inlet Damper Targ Pulse
      Air Inlet Damper Actual Pulse
      OK
      When the recirculation/fresh switch is operated, the actual pulse changes following the target pulse.
      Result
      Result Proceed to
      Target pulse changes but actual pulse does not change A
      Target pulse and actual pulse do not change B
      Actual pulse changes following the target pulse (When troubleshooting according to the DTC) C
      Actual pulse changes following the target pulse (When troubleshooting according to Problem Symptoms Table) D

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    C

    RECONFIRM DTC OUTPUT Click here

    D

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    A

  2. REPLACE BLOWER DAMPER SERVO SUB-ASSEMBLY (AIR INLET)


    1. Replace the blower damper servo sub-assembly (air inlet).

      Click here

      Tech Tips

      Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or known good one and check that the condition returns to normal.

    2. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1442/42 is output A
      DTC B1442/42 is not output B

    B

    END (BLOWER DAMPER SERVO SUB-ASSEMBLY (AIR INLET) WAS DEFECTIVE)

    A

  3. REPLACE AIR CONDITIONING HARNESS ASSEMBLY


    1. Replace the air conditioning harness assembly.

      Click here

      Tech Tips

      Since the air conditioning harness assembly cannot be inspected while it is removed from the vehicle, replace the air conditioning harness assembly with a new or known good one and check that the condition returns to normal.

    2. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1442/42 is output A
      DTC B1442/42 is not output B

    A

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    B

    END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)

  4. RECONFIRM DTC OUTPUT


    1. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1442/42 is output A
      DTC B1442/42 is not output B

    A

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    B

    USE SIMULATION METHOD TO CHECK Click here